The amphibians are a class of vertebrates like the mammals, birds, reptiles and fish. In the German language they are also called Lurche. They are divided into three orders: creeping amphibians, frogs and tailed amphibians. Scientists assume: Hundreds of millions of years ago, amphibians were the first creatures to live on land.
The word amphibian comes from the Greek and means double-lived. This is because most amphibians live in water when they are young, breathing through gills like fish. As they get older, amphibians move on land and then live on land and in water. Then, like humans, they breathe through lungs.
Her skin is thin and bare. There are hardly any calluses like we humans have on the soles of our feet, for example. The skin can be smooth and moist or dry with warts. Some amphibians have glands that can secrete venom. This protects them from enemies.
Most amphibians lay eggs. They lay these eggs, also called spawn, in the water. Then the larvae hatch out. The salamanders are an exception. They give birth to real larvae or even live young.
Amphibians are cold-blooded animals: their body temperature is always changing because it adapts to the temperature of its environment. This is important so that they do not get cold in the water and in the mountains.
How do amphibians live?
What is most striking about amphibians is the transformation they undergo throughout life. This is called “metamorphosis”: larvae hatch from the eggs, which breathe with gills. Later the lungs develop. A skeleton also grows. It is similar to that of mammals but has no ribs. When amphibians transition from life in the water to life on land, they breathe with their lungs and through their skin. The gills then grow back.
Amphibians live dangerously. They are the most important source of food for many animal species. They cannot defend themselves. But many are very good at camouflage. Others defend themselves with their poisonous body fluids, which they exude through the skin. These amphibians are often strikingly colored. Your predators should remember this and leave the corresponding amphibians alone next time. In order not to become extinct, the amphibians have to produce a large number of young.
In winter, amphibians hibernate. This means that they shed as much liquid as possible from their body and become very rigid as a result. Your skin then becomes dry and rough. When the temperature rises, they become mobile again.
What internal organs do amphibians have?
The internal organs of amphibians are the same as those of reptiles. In addition to the digestive organs, there are two kidneys that remove urine from the blood. The joint body outlet for faeces and urine is called the “cloaca”. The female also lays her eggs through this exit.
Amphibians have a special circulatory system and a simpler heart than mammals and birds. As in reptiles, the fresh blood mixes with the used blood in the heart. However, the heart of the amphibian is somewhat simpler than that of the reptile.
How do you classify amphibians?
The most common are the frogs. Among them are the frogs, toads and toads. Their young are called tadpoles. Their tail regresses during metamorphosis. Their hind legs become much stronger than their front legs. They feed on live insects, mollusks, spiders and arthropods, which they swallow whole. Anurans live on every continent except Antarctica and some other areas where it is too cold.
The tailed amphibians are quite rare. They are often divided into salamanders, which tend to live on land, and newts, which tend to live in the water. Their body is elongated and has a tail. The four legs are about the same size. They don’t hop or jump, they run. They have more vertebrae than the frogs. Tailed amphibians don’t like too much cold or heat. That’s why they don’t exist in Africa, South Asia, or Australia. There are only a few very special species in South America.
The creeping amphibians are even rarer. They are also called blind burrows. They look like earthworms, but they aren’t. They see poorly and can only distinguish between light and dark. They live in the tropics and subtropics, i.e. in parts of Central America, South America, Africa, and Asia. So they are not found in North America and Europe.